1. Field of the Invention
This invention relates generally to single sideband signal receivers, and more particularly is directed to a circuit for automatic frequency control of the carrier frequency demodulator thereof.
2. Description of the Prior Art
As is well-known in the art of single sideband communication, a transmitted single sideband signal does not contain a carrier frequency component. A single sideband signal also lacks any other constant level component by means of which the carrier frequency might be identified or followed by a single sideband receiver. As a result, the tuning of a single sideband receiver has been restricted to manual adjustment of the local or carrier frequency oscillator. However, manual adjustment is troublesome, and in the case of a "drifting" signal, manual tuning adjustment requires constant attention and considerable skill on the part of the operator.